Also the main killer is exploding HE rounds not burning propellant, and blowout panels are proven to work against them comparfed to a carousel full of HE rounds.
There are lots of variations on what happens when a tank is hit and penetrated and it largely depends on a lot of things... where it hits and what is in the tank and where.
The T-72 and other T series tanks got a bad reputation for exploding with their turrets blowing off when penetrated, and that was obviously because such vehicles only have half their ammo in their autoloader and the rest is inside the crew compartment in the turret and next to the driver.
I would add that the Abrams and also most western tanks also have ammo in the crew compartments and when they were penetrated were just as vulnerable to being destroyed too.
When there is no ammo outside the autoloader in a T-72 or T-90 then they didn't explode normally even when the turret or hull were penetrated.
For the Soviet ammo it was worse because the propellent does not have a full length brass case, so hot sparks or flame or hot fragments landing on the rounds in the tank immediately set off the propellent, but turrets could be blown off the T-54 and T-55 and T-62, all of which used brass propellent cases.
HE round generally only explode if hit directly... which is easier against the Abrams because the rounds are exposed in the turret bustle.
Otherwise it takes a few minutes of the tank burning for the HE and HEAT rounds to cook off and explode... the crew would normally have already bailed before that happened.
Also your point is kind of moot since if an APFSDS penetrates the crew compartment from the front, it will shatter after penetrating and bounce around the compartment, killig the crew plus incinerating them if its DU.
Not really... APFSDS cores are design not to shatter... because shattering means they are no longer able to penetrate any useful amount of armour, so most of the time it will exit the other side of the vehicle spraying small fragments and pieces of armour but most tanks have an inner anti spall liner made of kevlar and nomex and similar materials and will also be wearing body armour also to protect them from fragments and hot material.
Most of the time the incinerated crews were the ones that couldn't get out as the propellent burned...
Blowout panels absolutely work for shots from the side and the crew of a western MBT are much better protected from dying from a cookoff if hit from the side.
They are a catch 22 type situation... they essentially require that the ammo is in the turret rear exposed to enemy fire, which makes it vulnerable to being hit.
As long as it remains a propellent fire it would allow the crew to escape the vehicle before the HE and HEAT rounds start exploding, but whether they save the crew or not that tank is going to burn out so tank down.